A remote control unit is provided that includes an annular touch sensor for manipulating an annular menuing system displayed on a display device. Further, privacy may be seriously infringed. In one aspect, at least a portion of the piezoelectric material not involved in signal transmission by transduction between RF and acoustic energy is removed from the device. The selector selects one of the internal clock signals to serve as a selection clock signal according to an enable signal. The system then displays content of the second window on a second surface of the 3D object.